1. Field of the Invention
The invention relates to a precast element of quartz and to a method for producing such a precast element.
2. Description of the Prior Art
A refractory brick material for coke ovens of the type mentioned initially is well-known from the German published application 29 47 182. It consists predominantly of SiO.sub.2 and a binding agent, it is suitable for mould-cast bricks and preferably for coke-oven walls produced in one piece.
Precast elements of the type mentioned initially can generally be employed at very high temperatures. In the ceramics industry they are used, for example, as kiln furniture, in the glass industry they are employed in regions which are not in contact with the molten glass, e.g. as curtain bricks.
In the case of the precast element of quartz of the type mentioned initially being used in coke ovens, it is desirable that the creep under pressure at high temperatures be as low as possible. In practical operation the partition walls of coke ovens built of precast elements of quartz of the type mentioned initially are pressure-loaded from above, among other things by the weight of the fully-loaded charging car. Moreover the stability under temperature change of the precast element should be as high as possible. In practical operation the hot partition walls come into renewed contact with cold wet coal with every charge, at decharging a cold-air shock occurs. Furthermore abrasion of the precast element should be low. Finally, use of the precast element in coke ovens requires good heat transmission, i.e. best possible thermal conductivity.
This is where the invention comes into its own. It has the object, under consideration of the above-mentioned requirements, to further develop the initially mentioned precast element of fused quartz in such a way that it can be produced conveniently and cheaply and contains as large as possible a fraction of amorphous SiO.sub.2.